Adjustable extension



Oct. 15. 1940- E. M. PFAusER AUJUSTABLE EXTENSION Filed June 3, 1939 2Sheets-Sheet l n ,so y

a yy 'MTNEYQS V06f. 15, l940- E. M. PFAl-JsER 2,218,319

ADJUSTABLE EXTENS ION Filed June 3, 1959 2 Sheets-Shee. 2

ATTORNEY y Patented Oct. 15, 19 40 UNITED STATES PATENT oEFlcE 2,218,319ADJUSTABLE EXTENSION Edward M.'Pi'auser, Elm Grove, Wis., assignor toBlackhawk Minco., Milwaukee, Wis., a corporation of WisconsinApplication June 3, 1939, Serial No. 277,155

` 14 claims. (o1. asi-98)' ject upon which work is being performed.,

Generally stated, an object of the present lvention is to provide animproved adjustable exo tension which may be quickly and convementlyelongated or shortened, and which is positively retained in adjustedcondition.

When utilizing mechanical or iiuid pressure becomes desirable to quicklyvary or adjust the length of the pressure transferring and sustainingprop or connection between the jack mechanism and the object upon whichthe work is being performed.` Many different types of these quickadjustable jack extensions have heretofore been proposed and used withsomesuccess, the prior devices have all been relatively objectiony ableeither because of their complicated and bulky construction, 'or becausethey were ineffective in actual use. In some of the more populai jackextensions of this type, variation in `length was obtained by utilizinga quickly releasable friction clamp coacting with the extension bar orspindle, and while this type of extension was relatively satisfactorywhen the pressure acting upon the opposite ends thereof was not toogreat, it would not positively resist extreme pressures andthe ble propwhich may be readily manufactured at moderate cost, and which may-alsobe utilized as Y a. mechanical jack assemblage.

A further specic object of this invention is to provide an 4extremelysturdy and simple adjustable jack extension, which: may be quickly andconveniently elongated or shortened to fit within a xed space, wherein'the relatively adjustable parts may be more slowly and accuratelydisplaced by means of a screw thread, and in which vsemblage of Fig.'1,taken along the line 3 3;

the parts are finally positively held in adjusted position againstpossible displacement.

Still another specic object of myinvention is to provide a new anduseful adjustable pressure sustaining prop, whereinnthe pressures aremost l electively resisted by the prop elements and in which theadjusting notches or threads may be easily formed with thread chasers.

These andother specific objects and advantages will be apparent from thefollowing detailed 10 description. l

A clear conception of several embodiments of my present invention, andof the mode of constructing and of manipulating adjustable exten-` sionsbuilt in accordance with my improvement, Il

may be had by referring to the drawings accompanying and forming apartof this speciiication wherein like reference characters designate' thesame or similar parts in the varioustviews.

Fig. 1 is 'a central longitudinal section through 20 one type of myimproved adjustable extensions, showing the relatively adjustableelements positively interconnected and in condition to resist endpressure;

Fig. 2 is a similar sectionthrough a portion of 25 the assemblage ofFig. 1, but showing the relatively adjustable elements disconnectedpreparatory to adjustment;

Fig. 3 is a transverse section through the as- 30 Fig. 4 is a transversesection through the cori-` necting block or member alone, depicting themethod of producing this member;

Fig. 5 is a central longitudinal section through another type of theimproved adjustable exten- 35 sion, showing the parts positioned as inFig. 1;

Fig. 6 is a similar section through a fragment of the assemblage of Fig.5, with the relatively adjustable parts disconnected;

Fig. -7. is a transverse section through the assemblage of Fig. 5, takenalong the line 1 1; and

Fig. 8 is a transverse section through the modified connecting block ofFigs. 5 to 7 inclusive.

8 along the major portion of the length thereof; an outer element orhousing 9 having an internal bore embracing but freely movable along andaround the crests of the threads 1 of the spindle 6; and a connectingmember or block I0 laterally slidably confined within a pocket II in thehousing 9 and having partial internal threads I2 forming transverselateral projections which are adapted to interlock with the notches 8formed by the spindle threads 1.

The spindle 6 may be of any suitable length and may also be either solidor hollow depending upon its diameter, and one end of the spindle 6 maybe provided with a detachable externally threaded head or sleeve I4which may be firmly but removably attached to the spindle end-by a driftpin I5. A work engaging member I6 of any desired type, may be detachablysecured to the external threads I1 of the spindle 6 as shown in Fig. 1,but it should be apparent that the sleeve I4 may be omitted and' thatthe work engaging member may be applied directly to the 'spindle y end.

The housing 9 which is adjustable along the spindle 6, is of durableconstruction, and has one end socketed and provided with internal screwthreads I8 for reception of the threaded end of a tubular member or pipeI9 of any-suitable length. Ordinarily, the opposite end of the pipe I9is also threaded for coaction with the end of one of the movableelements of either a hydraulicor a mechanical jack, or the oppositethreaded pipe end may be attached to another work engaging member I6when the device is employed merely as a shore or prop. The exterior ofthe socketed lend 20 of the housing 9 may be formed polygonal, as forinstance hexagonal as shown inFlg. 3, in order to facilitate applicationof a wrench, but this formation is not essential.

The interconnecting block I which is slidably confined within thehousing pocket II as shown in Fig. 3, is of rectangular shape, and isnormally urged toward the spindle 6 so as to cause the .blockprojections or threads I2 to enter the spindle notches 8 as in Fig. l,by means of a pair of helical compression springs 2l coacting withrecesses 22 in the block I0 and reacting against al closure plate 23secured to the housing 9 over the pocket II by means of drive screws 24.The end of the threaded spindle 6 remote from the sleeve I4 may beprovided with a stop pin 25 which is engageable with the correspondingside of the block I0 in order to prevent accidental complete separationof the housing 9 and spindle 6 during relative quick adjustment of theseelements.

During manufacture of the blocks i8, and in order to insure sufficientstrength and desired accuracy in the formation thereof, these blocks arepreferably produced from solid metal blocks having the desired size andshape. Each block is. preferably initially bored and internally threadedas indicated by the dot-anddash circles 25 in Figs. 4 and 8, after whichthe block may be set in a jig and finally bored o ifcenter along thecircle 26. The diameter of the nal bore is somewhat larger than thelarger diand the recesses 22 may be formed either before or afte'r theblocks Il! are bored.

When my improved adjustable extension has been properly constructed andassembled, a work engaging member I6 of any desired type, may be appliedto the threaded sleeve I4, and a pipe I9 of any desired length may beapplied to the inin conjunction with Ja hydraulic ram or a jack, the endof the pipe I9 remote from the housing 9 may be connected to one of therelatively movable elements of the ram or jack. The overall length ofthe jack and extension may then be quickly adjusted to initially roughlyfit the vwork, by merely pressing the block I0 against the springs .2|until the thread projections I2 are disengaged from the'notches 8 of thespindle thread 1 as in Fig. 2, and by thereafter sliding the block I8and housing 9 as a unit along the spindle 8 in either direction untilthe work engaging faces of the jack and of the member I6 are inapproximately the desired position. The block I0 may thenbe released topermit the springs 2I to return the same to interlocking position asshown in Fig.`1, and more accurate final adjustment of the length of theassemblage may then be secured by relatively rotating the housing 9 andspindle 6 to cause the block I0 to revolve about the spindle threads 1.When the desired length of the assemblage has been thus finallyobtained, pressure may be applied tothe end of the pipe I9 -in order toperform the work, and this pressure will be positively'transmittedthrough the housing 9, block I0,l spindle B, sleeve I4, and member I6 tothe pressure receiving object, without danger of slippage-between theextension elements.

Since the block I0 of the assemblage shown in Figs. 1 to 4 inclusivecannot be readily finished internally with a screw thread chaser, due tothe use ofsquare threads, it may be desirable to form the screw andblock as shown in the modified assemblage of Figs. 5 to 8 inclusive.This modied assemblage comprises a spindlel 6' havling externalY screwthreads 1 of the acme type having included'angles of approximately 29and providing a series 'of transverse tapered notches 8' along the majorportion of its length; a housing 9' embracing but movable freely alongand about the crests of the threads 1'; and a block I0 slidablyconfinedin an inclined pocket II' in the housing 9' and having partialinternal threads /I 2 forming transverse tapered projections adapted tointerlock with vthe notches 8' formed on the spindle 6. In constructingthe modified assemblage, the inclination of the pocket II relative to aplane perpendicular to the spindle axis, should preferably be one-halfof the included thread angle, so that when pressure is applied to theends of the prop, this pressure will be transmitted from the spindle 6'to the block I0 and from the latter to the housing 9' without forcingthe block away from the spindle. For example, if the included angle ofthe threads 1 is twenty-nine degrees, the angle of inclination of thepocket II' shouldbe fourteen and onehalf degrees. In other respects, theconstruction and operation of the modified assemblage is substantiallylike that of Figs. l to 4 inclusive, but

` the modified structure is susceptible of being more tei-nal threadsI8. If the device is to be utilized in the extension itself. The threadprojections of the interconnecting block may, in each case, be readilyand accurately formed, and serves to positively interconnect the housingand spindle when the springs I2 are effective. This block may, however,be quickly and conveniently released from the spindle so as to permitrelative adjustment of thespindle and housing, and by virtue of the factthat the projections I2, I2' are actual portions of true screw threads,the housing mayalso be rotated about the spindle for purposes of fineradjustment. The modified thread projections I2 may be .readily formedwith a thread chaser, and will eiectively transmit pressure withoutslippage. As previously indicated, the improved assemblage may beutilized either as a jack for creating and applying pressure, or as anextension for a ram or jack, or as a shore or prop. The assemblage canbe accurately machined at relatively low cost, so `as to insure mosteiiicient operation thereof, andhas actually proven highly successful incommercial use. As heretofore indicated, the work engaging member I6 maybe of any desired type, and the intermediate pipes I9 may be of anydesired length.

It should be understood that it is not desired to limit this inventionto the exact details of construction or to the precise mode of use,herein shown and described, for various modiilcations within the scopeof the claims may occur to persons skilled in the art.

I claim:

1. An adjustable extension comprising, an elongated element havingnotches 'extending in series therealong, a housing element embracingsaid elongated element and being movable therealong, and a member havingan opening through which said elongated element is freely axiallymovable,

said member being slidable Within said housing element laterally of saidelongated element and having a series of projections at one side of saidopening interlockable with said notches to positively connect saidelements.

2. An adjustable extension comprising, a-n elongated element having ascrew thread forming notches extending in series therealong, a housingelement embracing said elongated 'element and being rotatable`thereaboutand movable therealong, and a member having a bore throughwhich said elongated element is freely axially shiftable, said memberbeing slidable within said housing element laterally of said elongatedelement and having a series of projections at one side of said boreinterlockable `with'said notches elongated element and having an openingthrough which said element is freely axially movable, said member beingslidable within said housing element laterally of said elongated elementand having a series of projections at one side of said openinginterlockable with said notches to positively connect said elements, andresilient means for constantly urging said member toward interlockingposition.

4. An adjustable extension comprising, an

elongated element having a screw thread forming notches extending inseries therealong, a housing element embracing and being rotatablethere'about and movable therealong, a member completely surrounding saidelongated element and having an opening through which said .element isfreely' axially shiftable, said member being slidable within saidhousing element laterally of said elongated element and having a seriesof projections at one side of said bore interlockable with said notchesand rotatable about said screw thread to posisaid elongated element`tively connect said elements, and spring means Y for constantly urgingsaid member toward interlocking position.

5. An adjustable extension comprising, an elongated spindle having anexternal screw thread,

a housing embracing said spindle and having a.

pocket therein, and a block slidably confined within said pocket andhaving a bore provided withpartial threads at one side only of said boreand engageable with said spindle threads to interlock said spindle andhousing, said bore being large enough to permit said block to beslid-away from said spindle sufficiently to interrupt the interlock andto permit relative sliding of said housing and spindle.

6. An adjustable extension comprising, an

elongated spindle having an external screwthread, a housing embracingsaid spindle and having a pocket therein, a blocklslidably conned withinsaid pocket and having a bore provided with partial threads at one sideonly of said bore engageable with said spindle threads to interlock saidspindle and housing,'said block completely surrounding said spindleandsaid bore being of sufficient diameter to permit said block to be slidaway from said spindle suiciently to interrupt the interlock4 and topermit relative sliding of said housing and spindle, and a spring forconstantly urging said block toward interlocking position. y

' 7. An adjustablev extension comprising, an

elongated externally threaded spindle having screw threads at one endforl interchangeable attachment of work engaging members, a housingembracing said spindle and having screw threads.

adapted for interchangeable reception of pressure applying pipes ofydifferent lengths, anda block completely surrounding said spindle andbeing slidably confined withinl said housing, said block having a boreand projections at one side only of said bore. engageable with thescrewthreads on said spindle for locking said housing in adjustedpositions.

8. An adjustable extension comprising, an elongated element having aseries of transverse tagated element having a series of transversetapered notches along a side thereof, a housing element -movablelongitudinally of said elongated element and a connecting memberslidable relative to said housing element and laterally of saidelongated element at an oblique angle, fsaidmember having taperedprojections interlockable with said notches and the angle of sliding ofsaidv member being approximately one-half of the ineluded angle of thetaper of said notches and oi' said projections.

10.v An adjustable extension comprising, an elongated element havingV-shaped screw threads forming tapered notches' extending in seriestherealong, a housing element embracing said elongated element, andbeing, rotatable thereabout and movable therealong, and a memberslidable Within said housing element laterally of said elongated elementand at an oblique angle relative to the longitudinal axis ofsaidIelongated element, said housing member having tapered projectionsinterlockable with said notches'and rotatable about said threads.

11. A'n adjustable extension comprising, an yelongated element havingV-shaped screw threads forming tapered notches extending in seriestherealong, a housing element embracing' said elongated element andbeing rotatable thereabout and movablel therealong, and a memberslidable within said housing element laterally of said elongated elementand at an oblique angle'` relative to the longitudinal axis of saidelongated I\element, said slidable member having tapered 'projectionsinterlockable with said notches and rotatable about said threads and theangle of sliding of said member relative to said elongated element beingapproximately one-halfof the included a-ngle of said threads.

' 12. An adjustable extension comprising, an elongated element havingscrew threads forming tapered notches extending in series therealong,

a housing element embracing-said elongated element and being revolvablcthereabout and movable therealong, and a member having a bore throughwhich said elongated element extends and being slidable within saidhousing element laterally of said elongated element and approximatelyparallel to the planesof corresponding sides of said notches. v

13. An adjustable extension comprising, an elongated element having aseries of tapered notches at one side thereof, a housing element movablealong said elongatedelement, and a member `slidable Within said housingelement laterally of said elongated element and at an oblique anglerelative to the longitudinal axis of the later, said member havingtapered projections cooperable with said notches ,and being movableapproximately parallel to the Iplanes of the corresponding pressureresisting sides of said notches.

14. An adjustable extension comprising, an elongated screw' threadedelement, a housing element movable along said elongated element, and amemberA having a bore through which said elongated element extends andwhich is provided with local projections cooperable with correspondingportionsr of the successive screw threads of said elongated element,said 'member being slidable in said housing element laterally of saidthreaded element and in a plane approximately parallel to correspondingsides of the successive threads.

EDWARD M. PFAUSER.

